E. coli bacteria solve sudoku puzzle

University students in Tokyo train a strain of bacteria to follow a sudoku puzzle grid.

What's more frightening: a strain of bacteria that can easily kill you, or one with problem-solving abilities? Students at the University of Tokyo have genetically engineered a strain of bacteria that can solve sudoku puzzles, according to New Scientist.

"Because sudoku has simple rules, we felt that maybe bacteria could solve it for us, as long as we designed a circuit for them to follow," explained team leader Ryo Taniuchi.

The scientists placed 16 types of E. coli bacteria in a four-by-four sudoku grid, giving each a unique genetic identity depending on the square it occupied. The bacteria were also able to express one of four colors to signify the numerical value of the square.

Bacteria occupying certain squares were assigned a value and corresponding color by the scientists, to replicate the small number of values that are already present in any sudoku puzzle.

So, how did the bacteria solve the puzzle? Communication. The bacteria that were assigned a value transmitted that value to bacteria in “unsolved” grid squares, and because the E. coli were programmed by the scientists only to accept signals from cells in the same row, column or block as themselves, the undifferentiated bacteria figured out which color to adopt based on a process of elimination.

This isn't the first time that bacteria have been able to successfully solve a puzzle. In 2008, a team of scientists trained E. coli to solve what they called the “burnt pancake problem." In an interview with NPR, Dr. Karmella Haynes joked about the possibility of teaching them sudoku in the future.

Haynes explained that the value in these experiments lies in addressing problems that require parallel processing capacity, or a large number of "mini computers" working together. Manipulating bacteria could also give scientists a better understanding of how to handle strains that become resistant to antibiotics.

But don't worry about Franken-bacteria that will escape the lab and take over the world, said Haynes.